The major objective of the Midwinter Conference of Immunologists is to provide an annual scientific meeting conducive to interaction between established senior scientists and new investigators, postdoctoral and graduate students. The goal of the conference is to communicate the most recent developments in the field of immunology. The Midwinter Conference of Immunologists has a long track record of organizing successful meetings. The 49th conference has been scheduled for January 23-26, 2010. The topics will cover an in depth analysis of important recent developments in innate and adaptive immune responses in infections and autoimmunity. Important developments of how the innate immune system recognizes danger signals and how its function can be disturbed in infections, tumors and in autoimmune diseases will be presented. New insights in the theoretical and molecular basis of immune regulation will be explored. Effector mechanisms for combating infectious pathogens will be addressed. Recent information on the essential role of T cell subsets in effective immune responses will be discussed. New perspectives in autoimmunity will discuss how autoimmune responses are generated and can be controlled. The speakers selected for the 49th Midwinter Conference are excellent and represent well-known scientists as well as upcoming young investigators. The program will allow ample time for discussion, exchange of ideas and establishment of collaborations. This conference is an outstanding venue for postdoctoral fellows and graduate students to meet established investigators. The 2010 conference promises to be as successful as previous Midwinter Conferences to generate novel ways to explore the immune system.